Target shooting is a sport which is enjoyed by many people throughout the world. Target shooting can range from simple backyard target practice for entertainment, to highly competitive shooting contests. One form of target shooting employs guns such as airsoft guns. Airsoft guns typically comprise replica firearms (rifles and pistols) which shoot plastic projectiles (also known as pellets) by way of compressed gas, electric motors, or spring-driven pistons. Common uses for airsoft guns are competitive gaming (similar to paintball), military simulations, target shooting, military training, and recreation. While similar in operation to BB guns, airsoft guns fire lightweight plastic projectiles 6 mm in diameter instead of metallic 4.5 mm BBs. Airsoft guns also typically have a muzzle velocity of less than 180 m/s (600 ft/s), compared to a BB gun which may have a muzzle velocity of 365 m/s (1200 ft/s) or more. The combination of the lighter projectiles and the reduced muzzle velocity means that airsoft guns are generally considered safe when used in a controlled environment and with safety equipment like protective eyewear. In many applications, airsoft guns are used in conjunction with targets such as paper targets, mechanical targets, and the like.